It is often desirable to transmit information on connections that can be available or blocked. For example, a connection may become overloaded (or even fail), and then come back up at some later time. Conventional message handling approaches can perform poorly in the presence of unreliable connections. For example, dropped event messages can lead to incorrect behavior in distributed processing. Alternative approaches, such as maintaining a centralized state (e.g., in a master server that provides state information on request to clients) can incur other disadvantages, such as increased overhead. Accordingly, it would be an advance in the art to provide improved utilization of connections that can be available or blocked.